دورية أكاديمية

Positron annihilation spectroscopy of chain-end-functionalized polystyrenes with definite numbers of benzyl alcohol and perfluorooctyl groups

التفاصيل البيبلوغرافية
العنوان: Positron annihilation spectroscopy of chain-end-functionalized polystyrenes with definite numbers of benzyl alcohol and perfluorooctyl groups
المؤلفون: Mahmoud, Kamal Reyad, El-Shehawy, Ashraf, Atta, Hoda
المصدر: Polímeros. January 2019 29(4)
بيانات النشر: Associação Brasileira de Polímeros, 2019.
سنة النشر: 2019
مصطلحات موضوعية: benzyl alcohol and perfluorooctyl groups, hyperbranched polymers, chain-end-functionalized polystyrene, doppler broadening, free volume, positron annihilation
الوصف: A series of well-defined chain-end-functionalized polystyrenes with a definite number of benzyl alcohol and perfluorooctyl groups [PS(BnOH)n & PS(BnORf)n, respectively] linearly aligned in a double line at the chain-ends were prepared and investigated using XRD, SEM, PALS and DBAR spectroscopy. XRD studies showed that PS(BnOH)n are crystalline and the degree of crystallinity increases with increasing the number of benzyl alcohol functionalities, while XRD pattern of PS(BnORf)n revealed that incorporating perfluorooctyl groups resulting in some fractions of polystyrene chains that were intercalated or broken between the interlayer spacing. PALS measurements yielded three lifetime components and the formation probabilities as well as lifetime of ortho-positronium in polymer series were found to be dependent on the chain-end polymer structure. DBAR measurements suggested that only one type of defect is present in the polymer samples.
نوع الوثيقة: article
وصف الملف: text/html
اللغة: English
تدمد: 0104-1428
DOI: 10.1590/0104-1428.04619
URL الوصول: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282019000400410
حقوق: info:eu-repo/semantics/openAccess
رقم الأكسشن: edssci.S0104.14282019000400410
قاعدة البيانات: SciELO
الوصف
تدمد:01041428
DOI:10.1590/0104-1428.04619